# Sample code

## GPIO

### Blinking LED

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"

#define LED_PIN PA_5
#define BUTTON_PIN PC_13

// Initialiization 
void setup(void) {
	RCC_PLL_init();
	SysTick_init();
	GPIO_init(LED_PIN, OUTPUT);    
}
	
int main(void) { 
	setup();
	
	while(1){
		delay_ms(500);  
		GPIO_write(LED_PIN, LOW);
		delay_ms(500);  
		GPIO_write(LED_PIN, HIGH);
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "ecSTM32F411.h"

#define LED_PIN 5
#define BUTTON_PIN 13

// Initialiization 
void setup(void) {
	RCC_PLL_init();
	SysTick_init();
	GPIO_init(GPIOA, LED_PIN, OUTPUT);    
}
	
int main(void) { 
	setup();
	
	while(1){
		delay_ms(500);  
		GPIO_write(GPIOA, LED_PIN, LOW);
		delay_ms(500);  
		GPIO_write(GPIOA, LED_PIN, HIGH);
	}
}
```

{% endtab %}

{% tab title="Arduino" %}

```cpp
// constants won't change. Used here to set a pin number:
const int ledPin =  LED_BUILTIN;// the number of the LED pin

// Variables will change:
int ledState = LOW;             // ledState used to set the LED

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0;        // will store last time LED was updated

// constants won't change:
const long interval = 1000;           // interval at which to blink (milliseconds)

void setup() {
  // set the digital pin as output:
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // here is where you'd put code that needs to be running all the time.

  // check to see if it's time to blink the LED; that is, if the difference
  // between the current time and last time you blinked the LED is bigger than
  // the interval at which you want to blink the LED.
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW) {
      ledState = HIGH;
    } else {
      ledState = LOW;
    }

    // set the LED with the ledState of the variable:
    digitalWrite(ledPin, ledState);
  }
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"

DigitalOut led(LED1);

int main() {
    while(1) {
        led = 1;
        wait(0.5)
        led=0;
        wait(0.5);
    }
}
```

{% endtab %}
{% endtabs %}

###

### LED with button

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"

#define LED_PIN PA_5
#define BUTTON_PIN PC_13

// Initialiization 
void setup(void) {
	RCC_HSI_init();
	// initialize the pushbutton pin as an input:
	GPIO_init(BUTTON_PIN, INPUT);  
	// initialize the LED pin as an output:
	GPIO_init(LED_PIN, OUTPUT);    
}
	
int main(void) { 
 	setup();
	int buttonState=0;
	
	while(1){
		// check if the pushbutton is pressed. Turn LED on/off accordingly:
		buttonState = GPIO_read(BUTTON_PIN);
		if(buttonState)	GPIO_write(LED_PIN, LOW);
		else 		GPIO_write(LED_PIN, HIGH);
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "ecSTM32F411.h"

#define LED_PIN 	5
#define BUTTON_PIN 13

// Initialiization 
void setup(void) {
	RCC_HSI_init();
	// initialize the pushbutton pin as an input:
	GPIO_init(GPIOC, BUTTON_PIN, INPUT);  
	// initialize the LED pin as an output:
	GPIO_init(GPIOA, LED_PIN, OUTPUT);    
}
	
int main(void) { 
 	setup();
	int buttonState=0;
	
	while(1){
		// check if the pushbutton is pressed. Turn LED on/off accordingly:
		buttonState = GPIO_read(GPIOC, BUTTON_PIN);
		if(buttonState)	GPIO_write(GPIOA, LED_PIN, LOW);
		else 		GPIO_write(GPIOA, LED_PIN, HIGH);
	}
}
```

{% endtab %}

{% tab title="Arduino" %}

```cpp
// constants won't change. They're used here to set pin numbers:
const int buttonPin = 2;     // the number of the pushbutton pin
const int ledPin =  13;      // the number of the LED pin

// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status

void setup() {
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);
  // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT);
}

void loop() {
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
  if (buttonState == HIGH) {
    // turn LED on:
    digitalWrite(ledPin, HIGH);
  } else {
    // turn LED off:
    digitalWrite(ledPin, LOW);
  }
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"

DigitalIn  button(USER_BUTTON);
DigitalOut led(LED1);

int main() {
    while(1) {
        if(!button) led = 1;
        else led = 0;
    }
}
```

{% endtab %}
{% endtabs %}

### Seven Segment

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"

#define BUTTON_PIN PC_13

// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	GPIO_init(BUTTON_PIN, INPUT);  
	sevensegment_init();
}
	
int main(void) { 
	setup();
	unsigned int cnt = 0;
		
	while(1){
		// display 7-segment 0 to 9
		sevensegment_decode(cnt % 10);
		// increase number with button push
		if(GPIO_read(BUTTON_PIN) == 0) {
			cnt++; 
			delay_ms(500);
		}
		if (cnt > 9) cnt = 0;
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "ecSTM32F411.h"

#define BUTTON_PIN 13

// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	GPIO_init(GPIOC, BUTTON_PIN, INPUT);  
	sevensegment_init();
}
	
int main(void) { 
	setup();
	unsigned int cnt = 0;
		
	while(1){
		// display 7-segment 0 to 9
		sevensegment_decode(cnt % 10);
		// increase number with button push
		if(GPIO_read(GPIOC, BUTTON_PIN) == 0) {
			cnt++; 
			delay_ms(500);
		}
		if (cnt > 9) cnt = 0;
	}
}
```

{% endtab %}

{% tab title="EC\_2" %}

```cpp
#include "ecSTM32F411.h"
#include "ecGPIO.h"
#include "ecPinNames.h"

#define BUTTON_PIN 13

// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	GPIO_init(GPIOC, BUTTON_PIN, INPUT);  
	sevensegment_init2();
}
	
int main(void) { 
	setup();
	unsigned int cnt = 0;
		
	while(1){
		// display 7-segment 0 to 9
		sevensegment_decode2(cnt % 10);
		// increase number with button push
		if(GPIO_read(GPIOC, BUTTON_PIN) == 0) {
			cnt++; 
			delay_ms(500);
		}
		if (cnt > 9) cnt = 0;
	}
}

/////////////////////////////////////////////////////
// Seven Segment Decoder 

void sevensegment_decode2(unsigned int num){
	// 7-segment Decoder 
	int number[11][8] = {
					{1,1,1,0,1,1,1,0},          //zero
					{0,0,1,0,0,1,0,0},          //one
					{1,0,1,1,1,0,1,0},          //two
					{1,0,1,1,0,1,1,0},          //three
					{0,1,1,1,0,1,0,0},          //four
					{1,1,0,1,0,1,1,0},          //five
					{1,1,0,1,1,1,1,0},          //six
					{1,0,1,0,0,1,0,0},          //seven
					{1,1,1,1,1,1,1,0},          //eight
					{1,1,1,1,0,1,1,0},          //nine
					{0,0,0,0,0,0,0,1}          //dot
	};
	
    	PinName_t sevenPins[] = { PA_5, PA_6, PA_7, PB_6, PC_7,  PA_9, PA_8, PB_10}
	// GPIO Write 
	GPIO_TypeDef* Port;
	unsigned int pin;
	unsigned int ledOut;

	for (int i = 0; i < 8; i++) { 
		ledOut = number[num][i];
		ecPinmap(sevenPins[i], Port, &pin);
		GPIO_write(Port, pin, ledOut)
	}

}



/////////////////////////////////////////////////////
// Seven Segment Initialization 

void sevensegment_init2(){
	// GPIO 7-segment pins 
    	PinName_t sevenPins[] = { PA_5, PA_6, PA_7, PB_6, PC_7,  PA_9, PA_8, PB_10};

	// GPIO Initialization
	GPIO_TypeDef* Port;
	unsigned int pin;

	for (int i = 0; i < 8; i++)
	{
		ecPinmap(sevenPins[i], Port, &pin);
        GPIO_init(Port, pin, OUTPUT);
		GPIO_mode(Port, pin, OUTPUT);
		GPIO_pupd(Port, pin, EC_PU);
	}
}

```

{% endtab %}

{% tab title="Arduino" %}

```cpp
// https://www.circuitbasics.com/arduino-7-segment-display-tutorial/

#include "SevSeg.h"
SevSeg sevseg; 

void setup(){
    byte numDigits = 1;
    byte digitPins[] = {};
    byte segmentPins[] = {6, 5, 2, 3, 4, 7, 8, 9};
    bool resistorsOnSegments = true;

    byte hardwareConfig = COMMON_CATHODE; 
    sevseg.begin(hardwareConfig, numDigits, digitPins, segmentPins, resistorsOnSegments);
    sevseg.setBrightness(90);
}

void loop(){
        sevseg.setNumber(4);
        sevseg.refreshDisplay();        
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"
 
    //pins are sorted from upper left corner of the display to the lower right corner
    //the display has a common cathode
    //the display actally has 8 led's, the last one is a dot 
DigitalOut led[8]={p18, p19, p17, p20, p16, p14, p15, p13};
 
 
    //each led that has to light up gets a 1, every other led gets a 0
    //its in order of the DigitalOut Pins above
int number[11][8]={
                    {1,1,1,0,1,1,1,0},          //zero
                    {0,0,1,0,0,1,0,0},          //one
                    {1,0,1,1,1,0,1,0},          //two
                    {1,0,1,1,0,1,1,0},          //three
                    {0,1,1,1,0,1,0,0},          //four
                    {1,1,0,1,0,1,1,0},          //five
                    {1,1,0,1,1,1,1,0},          //six
                    {1,0,1,0,0,1,0,0},          //seven
                    {1,1,1,1,1,1,1,0},          //eight
                    {1,1,1,1,0,1,1,0},          //nine
                    {0,0,0,0,0,0,0,1}          //dot
                  };
 
 
int main() {
    while (1) {
            //all led's off
        for(int i = 0; i<8;i++){led[i] = 0;}
        
            //display shows the number in this case 6
        for (int i=0; i<8; i++){led[i] = number[6][i];}         //the digit after "number" is displayed
 
            //before it gets tired
        wait(0.5);
    
    }
}
```

{% endtab %}
{% endtabs %}

## EXTI Interrupt

### Button External Interrupt

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"

#define LED_PIN	PA_5
#define BUTTON_PIN PC_13

// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	GPIO_init(LED_PIN, OUTPUT);
	GPIO_init(BUTTON_PIN, INPUT);
	GPIO_pupd(BUTTON_PIN, EC_PD);
	// Priority Highest(0) External Interrupt 
	EXTI_init(BUTTON_PIN, FALL, 0);
}

int main(void) {
	setup();
	while (1) {}
}

//EXTI for Pin 13
void EXTI15_10_IRQHandler(void) {
	if (is_pending_EXTI(BUTTON_PIN)) {
		LED_toggle();
		// must include clear pending
		clear_pending_EXTI(BUTTON_PIN); 
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "ecSTM32F411.h"

#define LED_PIN	5
#define BUTTON_PIN 13

// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	GPIO_init(GPIOA, LED_PIN, OUTPUT);
	GPIO_init(GPIOC, BUTTON_PIN, INPUT);
	GPIO_pupd(GPIOC, BUTTON_PIN, EC_PD);
	// Priority Highest(0) External Interrupt 
	EXTI_init(GPIOC, BUTTON_PIN, FALL, 0);
}

int main(void) {
	setup();
	while (1) {}
}

//EXTI for Pin 13
void EXTI15_10_IRQHandler(void) {
	if (is_pending_EXTI(BUTTON_PIN)) {
		LED_toggle();
		clear_pending_EXTI(BUTTON_PIN); 
	}
}
```

{% endtab %}

{% tab title="Arduino" %}

```cpp
const byte ledPin = 13;
const byte interruptPin = 2;
volatile byte state = LOW;

void setup() {
	pinMode(ledPin, OUTPUT);
	pinMode(interruptPin, INPUT_PULLUP);
	attachInterrupt(digitalPinToInterrupt(interruptPin), blink, CHANGE);
}

void loop() {
	digitalWrite(ledPin, state);
}

void blink() {
	state = !state;
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"

InterruptIn button(USER_BUTTON); 
DigitalOut  led(LED1);

void pressed()
{
    led = 1; 
}

void released(){
    led = 0;
}

int main()
{
    button.fall(&pressed);
    button.rise(&released);
    while (1);
}
```

{% endtab %}
{% endtabs %}

## SysTick Interrupt

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"
//#include "stm32f411xe.h"
//#include "ecGPIO2.h"
//#include "ecRCC2.h"
//#include "ecSysTick2.h"


// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	sevensegment_init();
}

int main(void) { 
	// Initialiization --------------------------------------------------------
	setup();
	int count = 0;	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		sevensegment_decode(count);
		delay_ms(1000);
		count++;
		if (count >10) count =0;
		SysTick_reset();
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "stm32f411xe.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecSysTick.h"

int count = 0;
// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	sevensegment_init();
}

int main(void) { 
	// Initialiization --------------------------------------------------------
		setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		sevensegment_decode(count);
		delay_ms(1000);
		count++;
		if (count >10) count =0;
		SysTick_reset();
	}
}
```

{% endtab %}

{% tab title="EC\_API" %}

```cpp
#include "EC_API.h"

EC_Ticker tick(1);
int count = 0;

// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	sevensegment_init();
}

int main(void) { 
	// Initialiization --------------------------------------------------------
		setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		sevensegment_decode(count);
		tick.Delay_ms(1000);
		count++;
		if (count ==10) count =0;
		tick.reset();
	}
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"

```

{% endtab %}
{% endtabs %}

## Timer Interrupt

### Timer Interrupt Example 1

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"
//#include "ecTIM2.h"


#define LED_PIN	PA_5
uint32_t _count = 0;

void setup(void);

int main(void) {
	// Initialization --------------------------------------------------
	setup();
	
	// Infinite Loop ---------------------------------------------------
	while(1){}
}


// Initialization
void setup(void){
	// System Clock = 84MHz
	RCC_PLL_init();				
	
	// LED Configuration
	GPIO_init(LED_PIN, OUTPUT);		

	// TIM2 Update-Event Interrupt every 100 msec 
	TIM_UI_init(TIM2, 100);			
}

void TIM2_IRQHandler(void){
	if(is_UIF(TIM2)){			// Check UIF(update interrupt flag)
		_count++;
		if (_count > 10) {
			LED_toggle();		// LED toggle every 1 sec
			_count = 0;
		}
		clear_UIF(TIM2); 		// Clear UI flag by writing 0
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "stm32f411xe.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecTIM.h"


#define LED_PIN	5
uint32_t _count = 0;
void setup(void);


int main(void) {
	// Initialization --------------------------------------------------
	setup();
	
	// Infinite Loop ---------------------------------------------------
	while(1){}
}


// Initialization
void setup(void){
	RCC_PLL_init();				// System Clock = 84MHz
	GPIO_init(GPIOA, LED_PIN, OUTPUT);	// calls RCC_GPIOA_enable()
	TIM_UI_init(TIM2, 1);			// TIM2 Update-Event Interrupt every 1 msec 
	TIM_UI_enable(TIM2);
}

void TIM2_IRQHandler(void){
	if(is_UIF(TIM2)){			// Check UIF(update interrupt flag)
		_count++;
		if (_count > 1000) {
			LED_toggle();		// LED toggle every 1 sec
			_count = 0;
		}
		clear_UIF(TIM2); 		// Clear UI flag by writing 0
	}
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"

Ticker     tick;
DigitalOut led(LED1);

void INT(){
    led = !led;      
}
int main(void){
    tick.attach(&INT, 1); // 1초마다 LED blink
    
    while(1);
}
```

{% endtab %}
{% endtabs %}

## PWM

### PWM\_ LED

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"
#include "math.h"


// Definition Button Pin & PWM Port, Pin
#define BUTTON_PIN PC_13
#define PWM_PIN PA_5

void setup(void);

int main(void) {
	// Initialization --------------------------------------------------
	setup();	
	
	// Infinite Loop ---------------------------------------------------
	while(1){
		LED_toggle();		
		for (int i=0; i<5; i++) {						
			PWM_duty(PWM_PIN, (float)0.2*i);			
			delay_ms(1000);
		}		
	}
}

// Initialiization 
void setup(void) {	
	RCC_PLL_init();
	SysTick_init();
		
	// PWM : TIM2_CH1 (PA_5 LED) of 20 msec  
	PWM_init(PWM_PIN);	
	PWM_period(PWM_PIN, 20);   // 20 msec PWM period
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "stm32f411xe.h"
#include "math.h"

// #include "ecSTM32F411.h"
#include "ecPinNames.h"
#include "ecGPIO.h"
#include "ecSysTick.h"
#include "ecRCC.h"
#include "ecTIM.h"
#include "ecPWM.h"

// Definition Button Pin & PWM Port, Pin
#define BUTTON_PIN 13
#define PWM_PIN PA_5

void setup(void);

int main(void) {
	// Initialization --------------------------------------------------
	setup();	
	
	// Infinite Loop ---------------------------------------------------
	while(1){
		LED_toggle();		
		for (int i=0; i<5; i++) {						
			PWM_duty(PWM_PIN, (float)0.2*i);			
			delay_ms(1000);
		}		
	}
}

// Initialiization 
void setup(void) {	
	RCC_PLL_init();
	SysTick_init();
		
	// PWM of 20 msec:  TIM2_CH1 (PA_5 AFmode)
	GPIO_init(GPIOA, 5, EC_AF);
	PWM_init(PWM_PIN);	
	PWM_period(PWM_PIN, 20);   // 20 msec PWM period
}
```

{% endtab %}

{% tab title="EC\_2022" %}

```cpp

#include "ecSTM32F411.h"
#define BUTTON_PIN 13

PWM_t pwm;
float duty = 0;
int count = 0;

// Initialiization 
void setup(void) {
	RCC_PLL_init();
	SysTick_init();
	GPIO_init(GPIOC, BUTTON_PIN, INPUT);
	GPIO_pupd(GPIOC, BUTTON_PIN, EC_PD);
	EXTI_init(GPIOC, BUTTON_PIN, FALL, 0);

	// PWM of 20msec:  TIM2_CH2 (PA_1)
	PWM_init(&pwm, GPIOA, 1);
	PWM_period_ms(&pwm, 20);
}


int main(void) { 
	setup();

	while(1){
		for (count= 0; count < 8; count++) {
			duty = 0.1 + 0.1 * count;	
			PWM_duty(&pwm, duty);
			delay_ms(500);
		}
	}
}

void EXTI15_10_IRQHandler(void) {  
	if (is_pending_EXTI(BUTTON_PIN)) {
		count = 0;
		clear_pending_EXTI(BUTTON_PIN); 
	}
}


```

{% endtab %}

{% tab title="Arduino" %}

```cpp
const int pwmPin = 11;   // PWM pin
const int buttonPin = 3;  // button pin

int buttonState = HIGH;

void setup() {
  pinMode(pwmPin, OUTPUT);
 
 // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(buttonPin), motorOperation, CHANGE);
}

void loop() {

  if (buttonState == LOW){
    for (int i = 0; i < 10; i++){
      analogWrite(pwmPin, 40 + 10*i);
      delay(100);
    }
  
    for (int i = 10; i > 0; i--){
      analogWrite(pwmPin, 40 + 10*i);
      delay(100);
    }
  }
  else{
    analogWrite(pwmPin, 0);
  }
}

void motorOperation(){
  buttonState = digitalRead(buttonPin);
}


```

{% endtab %}
{% endtabs %}

### PWM \_ DC Motor \_Example 1 (Pause)

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"
#include "math.h"

#define DIR_PIN PC_2
#define DIR_PIN_2 PC_3
#define PWM_PIN PA_0
#define BUTTON_PIN PC_13

uint8_t pause_flag = 1;

uint32_t motorDIR=0;
float motorDuty=0.5f;

void setup(void);

int main(void) {
	// Initialiization --------------------------------------------------------
	setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while (1){
		PWM_duty(PWM_PIN, motorDuty);
	
		delay_ms(500);
	}
}


// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	
	// External Interrupt Button input: Falling, Pull-Up
	GPIO_init(BUTTON_PIN, INPUT);
	GPIO_pupd(BUTTON_PIN, EC_PU);
	EXTI_init(BUTTON_PIN, FALL, 0);

	// DIR pin Configuration
	GPIO_init(DIR_PIN, OUTPUT);
	GPIO_write(DIR_PIN, LOW);	
	GPIO_init(DIR_PIN_2, OUTPUT);
	GPIO_write(DIR_PIN_2,HIGH);	
	
	// PWM Configuration
	PWM_init(PWM_PIN);
	PWM_period_ms(PWM_PIN, 1);		// PWM period: 1msec
}

void EXTI15_10_IRQHandler(void)
{
	if(is_pending_EXTI(BUTTON_PIN)){
		//When Button is pressed, it should PAUSE or CONTINUE motor run (flag)
		pause_flag ^= 1;
		motorDuty *= (float)pause_flag;

		// Clear EXTI Pending
		clear_pending_EXTI(BUTTON_PIN);
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "stm32f4xx.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecTIM.h"
#include "ecPWM.h"
#include "ecPinNames.h"
#include "ecEXTI.h"
#include "ecUART.h"

#define DIR_PIN 2
#define MOTOR PA_0

float duty = 0.5f;
uint8_t pause_flag = 1;

void setup(void);

int main(void) {
	// Initialiization --------------------------------------------------------
	setup();
	printf("Hello Nucleo\r\n");
	
	// Inifinite Loop ----------------------------------------------------------
	while (1){
		PWM_duty(PA_0, duty);
	}
}

// Initialiization 
void setup(void)
{
	RCC_PLL_init();

	//UART2 Configuration
	UART2_init();
	
	// External Interrupt Button input: Falling, Pull-Up
	GPIO_init(GPIOC, BUTTON_PIN, INPUT);
	GPIO_pupd(GPIOC, BUTTON_PIN, EC_PU);
	EXTI_init(GPIOC, BUTTON_PIN, FALL, 0);

	// Direction Output Configuration
	GPIO_init(GPIOC, DIR_PIN, OUTPUT);
	GPIO_write(GPIOC, DIR_PIN, 0);

	// PWM Configuration
	PWM_init(PA_0);
	PWM_period_ms(PA_0, 1);		// PWM period: 1msec
}

void EXTI15_10_IRQHandler(void)
{
	if(is_pending_EXTI(BUTTON_PIN)){
		//When Button is pressed, it should PAUSE or CONTINUE motor run (flag)
		pause_flag ^= 1;
		duty *= (float)pause_flag;

		// Clear EXTI Pending
		clear_pending_EXTI(BUTTON_PIN);
	}
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"
#include "motordriver.h"

Motor A(D11, PC_8); // pwm, dir
Motor B(D12, PD_2); // pwm, dir

int main() {
    while (1) {
        // For speed test.
        for (float s= 0; s < 1.0f ; s += 0.1f) {
			A.forward(s); 
            wait(1);
		}

		A.stop();
        wait(3);

        for (float s= 0; s < 1.0f ; s += 0.1f) {
			A.backward(s);
            wait(1);
       }
    }
}
```

{% endtab %}
{% endtabs %}

### PWM \_ DC Motor\_Example 2 (motor DIR)

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"
#include "math.h"

#define DIR_PIN PC_2
#define DIR_PIN_2 PC_3
#define PWM_PIN PA_0
#define BUTTON_PIN PC_13

uint8_t pause_flag = 1;

uint32_t motorDIR=0;
float motorDuty=0.5f;

void setup(void);

int main(void) {
	// Initialiization --------------------------------------------------------
	setup();
	//printf("Hello Nucleo\r\n");
	
	// Inifinite Loop ----------------------------------------------------------
	while (1){
		// For Motor Driver LS9110
		//float duty = fabs(motorDIR - motorDuty); // duty with consideration of DIR=1 or 0
		//PWM_duty(PWM_PIN, duty);
		
		// For Motor Driver L298N 
		GPIO_write(DIR_PIN,motorDIR);
		GPIO_write(DIR_PIN_2,!motorDIR);
		PWM_duty(PWM_PIN, motorDuty);
				
		delay_ms(500);
	}
}


// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	//UART2 Configuration
	//UART2_init();
	
	// External Interrupt Button input: Falling, Pull-Up
	GPIO_init(BUTTON_PIN, INPUT);
	GPIO_pupd(BUTTON_PIN, EC_PU);
	EXTI_init(BUTTON_PIN, FALL, 0);

	// Direction Output Configuration
	GPIO_init(DIR_PIN, OUTPUT);	
	GPIO_write(DIR_PIN, LOW);  // For LS9110
	GPIO_init(DIR_PIN_2, OUTPUT);

	
	// PWM Configuration: 1msec period
	PWM_init(PWM_PIN);
	PWM_period_ms(PWM_PIN, 1);	
}

void EXTI15_10_IRQHandler(void)
{
	if(is_pending_EXTI(BUTTON_PIN)){
		//When Button is pressed, changes motor DIR
		motorDIR^=1;

		// Clear EXTI Pending
		clear_pending_EXTI(BUTTON_PIN);
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "stm32f4xx.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecTIM.h"
#include "ecPWM.h"
#include "ecPinNames.h"
#include "ecEXTI.h"
#include "ecUART.h"

#define DIR_PIN 2
#define MOTOR PA_0

float duty = 0.5f;
uint8_t pause_flag = 1;

void setup(void);

int main(void) {
	// Initialiization --------------------------------------------------------
	setup();
	printf("Hello Nucleo\r\n");
	
	// Inifinite Loop ----------------------------------------------------------
	while (1){
		PWM_duty(PA_0, duty);
	}
}

// Initialiization 
void setup(void)
{
	RCC_PLL_init();

	//UART2 Configuration
	UART2_init();
	
	// External Interrupt Button input: Falling, Pull-Up
	GPIO_init(GPIOC, BUTTON_PIN, INPUT);
	GPIO_pupd(GPIOC, BUTTON_PIN, EC_PU);
	EXTI_init(GPIOC, BUTTON_PIN, FALL, 0);

	// Direction Output Configuration
	GPIO_init(GPIOC, DIR_PIN, OUTPUT);
	GPIO_write(GPIOC, DIR_PIN, 0);

	// PWM Configuration
	PWM_init(PA_0);
	PWM_period_ms(PA_0, 1);		// PWM period: 1msec
}

void EXTI15_10_IRQHandler(void)
{
	if(is_pending_EXTI(BUTTON_PIN)){
		//When Button is pressed, it should PAUSE or CONTINUE motor run (flag)
		pause_flag ^= 1;
		duty *= (float)pause_flag;

		// Clear EXTI Pending
		clear_pending_EXTI(BUTTON_PIN);
	}
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"
#include "motordriver.h"

Motor A(D11, PC_8); // pwm, dir
Motor B(D12, PD_2); // pwm, dir

int main() {
    while (1) {
        // For speed test.
        for (float s= 0; s < 1.0f ; s += 0.1f) {
			A.forward(s); 
            wait(1);
		}

		A.stop();
        wait(3);

        for (float s= 0; s < 1.0f ; s += 0.1f) {
			A.backward(s);
            wait(1);
       }
    }
}
```

{% endtab %}
{% endtabs %}

## Stepper Motor

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"
#include "math.h"
//#include "ecStepper2.h"

void setup(void);
	
int main(void) { 
	// Initialiization --------------------------------------------------------
	setup();
	
	Stepper_step(2048, 1, FULL);  // (Step : 1024, Direction : 0 or 1, Mode : FULL or HALF)
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){;}
}

// Initialiization 
void setup(void)
{	
	
	RCC_PLL_init();                                 // System Clock = 84MHz
	SysTick_init();                                 // Systick init
	
	EXTI_init(BUTTON_PIN,FALL,0);             // External Interrupt Setting
	GPIO_init(BUTTON_PIN, EC_DIN);           // GPIOC pin13 initialization

	Stepper_init(PB_10,PB_4,PB_5,PB_3); // Stepper GPIO pin initialization
	Stepper_setSpeed(5);                          //  set stepper motor speed
}

void EXTI15_10_IRQHandler(void) {  
	if (is_pending_EXTI(BUTTON_PIN)) {
		Stepper_stop();
		clear_pending_EXTI(BUTTON_PIN); // cleared by writing '1'
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "stm32f411xe.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecTIM.h"
#include "ecEXTI.h"
#include "ecSysTick.h"
#include "ecStepper.h"

void setup(void);
	
int main(void) { 
	// Initialiization --------------------------------------------------------
	setup();
	
	Stepper_step(2048, 1, FULL);  // (Step : 1024, Direction : 0 or 1, Mode : FULL or HALF)
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){;}
}

// Initialiization 
void setup(void)
{	
	
	RCC_PLL_init();                                 // System Clock = 84MHz
	SysTick_init();                                 // Systick init
	
	EXTI_init(GPIOC,BUTTON_PIN,FALL,0);             // External Interrupt Setting
	GPIO_init(GPIOC, BUTTON_PIN, EC_DIN);           // GPIOC pin13 initialization

	Stepper_init(GPIOB,10,GPIOB,4,GPIOB,5,GPIOB,3); // Stepper GPIO pin initialization
	Stepper_setSpeed(5);                          //  set stepper motor speed
}

void EXTI15_10_IRQHandler(void) {  
	if (is_pending_EXTI(BUTTON_PIN)) {
		Stepper_stop();
		clear_pending_EXTI(BUTTON_PIN); // cleared by writing '1'
	}
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
```

{% endtab %}
{% endtabs %}

## Timer Input Capture: Ultrasonic Distance Sensor

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"
#include "math.h"

uint32_t ovf_cnt = 0;//count over count
float distance = 0;
float timeInterval = 0;
float time1 = 0;//start time
float time2 = 0;//end time

#define TRIG PA_6 //pwm
#define ECHO PB_6 //echo


void setup(void);

int main(void){
	int count_test=0;
	setup();
	printf("Start LAB_TIMER_ICAP\r\n");
	while(1){
		distance = (float) timeInterval * 340.0 / 2.0 /10.0; 	// [mm] -> [cm]
		printf("%.2f cm\r\n", distance);//display distance
		delay_ms(1000);//0.5sec delay
	}
}

void TIM4_IRQHandler(void){
	if(is_UIF(TIM4)){                     // Update interrupt
		ovf_cnt++;													// overflow count
		clear_UIF(TIM4);  							    // clear update interrupt flag
	}
	if(is_CCIF(TIM4, 1)){ 								// TIM4_Ch1 (IC1) Capture Flag. Rising Edge Detect
		time1 = ICAP_capture(TIM4,1);									// Capture TimeStart
		clear_CCIF(TIM4, 1);                // clear capture/compare interrupt flag 
	}								                      
	else if(TIM4,2){ 									// TIM4_Ch2 (IC2) Capture Flag. Falling Edge Detect
		time2 = ICAP_capture(TIM4,2);									// Capture TimeEnd
		timeInterval = ((time2-time1)+ovf_cnt*((TIM4->ARR)+1))/100.0; 	// (10us * counter pulse -> [msec] unit) Total time of echo pulse
		ovf_cnt = 0;                        // overflow reset
		clear_CCIF(TIM4,2);								  // clear capture/compare interrupt flag 
	}
}

void setup(){

	RCC_PLL_init(); 
	SysTick_init();//1msec
	UART2_init1();
	GPIO_otype(TRIG, 0);//push pull
	GPIO_pupd(TRIG,0);//NO pull-up pull-down
	GPIO_ospeed(TRIG,EC_FAST);//FAST SPEED
	
	
  
// PWM configuration ---------------------------------------------------------------------	
	PWM_init(TRIG);			// PA_6: Ultrasonic trig pulse
	PWM_period_us(TRIG, 50000);    // PWM of 50ms period. Use period_us()
	PWM_pulsewidth_us(TRIG, 10);   // PWM pulse width of 10us
	
	
// Input Capture configuration -----------------------------------------------------------------------	
	ICAP_init(ECHO);    	// PB_6 as input caputre
	GPIO_pupd(ECHO,0);//NO pull-up pull-down
 	ICAP_counter_us(ECHO, 10);   	// ICAP counter step time as 10us
	ICAP_setup(ECHO, 1, IC_RISE);  // TIM4_CH1 as IC1 , rising edge detect
	ICAP_setup(ECHO, 2, IC_FALL);  // TIM4_CH2 as IC2 , falling edge detect

}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "stm32f411xe.h"
#include "math.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecTIM.h"
#include "ecUART_simple_student.h"
#include "ecSysTick.h"

uint32_t ovf_cnt = 0;
uint32_t ccr1 = 0;
uint32_t ccr2 = 0;
float    period = 0;

void setup(void);

int main(void){
	
	setup();
	while(1){
		printf("period = %f[msec]\r\n", period);		// print out the period on TeraTerm
		delay_ms(100);
	}
}


void setup(void) {	
	// Configuration Clock PLL
	RCC_PLL_init();
	
	// UART2 Configuration to use printf()
	UART2_init();
	
	// SysTick Configuration to use delay_ms()
	SysTick_init();

	// Input Capture Configuration PA_0(TIM2, 1)
	ICAP_init(PA_0);
	
	// Priority Configuration
	NVIC_SetPriority(TIM2_IRQn, 2);						// Set the priority of TIM2 interrupt request
	NVIC_EnableIRQ(TIM2_IRQn);							// TIM2 interrupt request enable
}

// Timer2 IRQ Handler (timer & Input Capture)
void TIM2_IRQHandler(void){
	if(is_UIF(TIM2)){                  // If Update-event interrupt Occurs
		// Handle overflow
		ovf_cnt++;
		
		clear_UIF(TIM2);   					// clear update-event interrupt flag
	}
	if(is_CCIF(TIM2, IC_1)){				// if CC interrupt occurs	
		// Calculate the period of 1Hz pulse
		ccr2 = ICAP_capture(TIM2, IC_1);						// capture counter value
		period = ((ccr2 - ccr1) + ovf_cnt * (TIM2->ARR + 1)) / 1000; 		// calculate the period with ovf_cnt, ccr1, and ccr2
		
		ccr1 = ccr2;
		ovf_cnt = 0;
		
		clear_CCIF(TIM2, IC_1);	// clear capture/compare interrupt flag ( it is also cleared by reading TIM2_CCR1)
	}
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"

Serial      pc(USBTX, USBRX, 9600);
PwmOut      trig(D10); // Trigger 핀
InterruptIn echo(D7);  // Echo 핀
Timer       tim;

int begin = 0;
int end = 0;

void rising(){
    begin = tim.read_us();
}

void falling(){
    end = tim.read_us();
}

int main(void){
    float distance = 0;
    
    trig.period_ms(60);     // period      = 60ms
    trig.pulsewidth_us(10); // pulse-width = 10us
    
    echo.rise(&rising);
    echo.fall(&falling);
    
    tim.start();
    
    while(1){
        distance =  (float)(end - begin) / 58; // [cm]
        pc.printf("Distance = %.2f[cm]\r\n", distance);
        wait(0.5);
    }
    
} 

```

{% endtab %}
{% endtabs %}

## ADC

{% tabs %}
{% tab title="EC\_2024\_single" %}

```cpp
#include "ecSTM32F4v2.h"
#include "math.h"
//#include "ecADC2.h"


//IR parameter//
uint32_t IR;

void setup(void);
	
int main(void) { 
	
	// Initialiization --------------------------------------------------------
	setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		printf("IR = %d \r\n",IR);
		printf("\r\n");
		delay_ms(1000);
	}
}

// Initialiization 
void setup(void)
{	
	RCC_PLL_init();                         // System Clock = 84MHz
	UART2_init();
	SysTick_init();
	
	// ADC setting
	ADC_init(PB_1);
	
}

void ADC_IRQHandler(void){
	if((is_ADC_OVR())){
		clear_ADC_OVR();
	}
	
	if(is_ADC_EOC()){       //after finishing sequence
			IR = ADC_read();
	}
}

```

{% endtab %}

{% tab title="EC\_2024\_multi" %}

```cpp
#include "stm32f411xe.h"
#include "ecGPIO2.h"
#include "ecRCC2.h"
#include "ecTIM2.h"
#include "ecSysTick2.h"
#include "ecUART2.h"
#include "ecADC2.h"
#include "ecPinNames.h"

//IR parameter//
uint32_t IR1_val, IR2_val;
int flag = 0;
PinName_t seqCHn[2] = {PB_0, PB_1};

void setup(void);
	
int main(void) { 
	

	// Initialiization --------------------------------------------------------
	setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		printf("IR1 = %d \r\n",IR1_val);
		printf("IR2 = %d \r\n",IR2_val);
		printf("\r\n");
		
		delay_ms(1000);
	}
}

// Initialiization 
void setup(void)
{	
	RCC_PLL_init();                         // System Clock = 84MHz
	UART2_init();							// UART2 Init
	SysTick_init();							// SysTick Init
	
	// ADC Init
	ADC_init(PB_0);
	ADC_init(PB_1);

	// ADC channel sequence setting
	ADC_sequence(seqCHn, 2);
	
}


void ADC_IRQHandler(void){
	if((is_ADC_OVR())){
		clear_ADC_OVR();
	}
	
	if(is_ADC_EOC()){       //after finishing sequence
		if (flag==0)
			IR1_val = ADC_read();  
		else if (flag==1)
			IR2_val = ADC_read();
			
		flag = !flag;
	}
}
```

{% endtab %}

{% tab title="EC\_single" %}

```cpp
#include "stm32f411xe.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecTIM.h"
#include "ecSysTick.h"
#include "ecUART.h"
#include "ecADC.h"
#include "ecPinNames.h"

//IR parameter//
uint32_t IR;

void setup(void);
	
int main(void) { 
	
	// Initialiization --------------------------------------------------------
	setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		printf("IR = %d \r\n",IR);
		printf("\r\n");
		delay_ms(1000);
	}
}

// Initialiization 
void setup(void)
{	
	RCC_PLL_init();                         // System Clock = 84MHz
	UART2_init();
	SysTick_init();
	
	// ADC setting
  ADC_init(PB_1);
	
}

void ADC_IRQHandler(void){
	if((is_ADC_OVR())){
		clear_ADC_OVR();
	}
	
	if(is_ADC_EOC()){       //after finishing sequence
			IR = ADC_read();
	}
}

```

{% endtab %}

{% tab title="EC\_multi" %}

```cpp
#include "stm32f411xe.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecTIM.h"
#include "ecSysTick.h"
#include "ecUART.h"
#include "ecADC.h"
#include "ecPinNames.h"

//IR parameter//
uint32_t IR1_val, IR2_val;
int flag = 0;
PinName_t seqCHn[2] = {PB_0, PB_1};

void setup(void);
	
int main(void) { 
	

	// Initialiization --------------------------------------------------------
	setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		printf("IR1 = %d \r\n",IR1_val);
		printf("IR2 = %d \r\n",IR2_val);
		printf("\r\n");
		
		delay_ms(1000);
	}
}

// Initialiization 
void setup(void)
{	
	RCC_PLL_init();                         // System Clock = 84MHz
	UART2_init();							// UART2 Init
	SysTick_init();							// SysTick Init
	
	// ADC Init
	ADC_init(PB_0);
	ADC_init(PB_1);

	// ADC channel sequence setting
	ADC_sequence(seqCHn, 2);
	
}


void ADC_IRQHandler(void){
	if((is_ADC_OVR())){
		clear_ADC_OVR();
	}
	
	if(is_ADC_EOC()){       //after finishing sequence
		if (flag==0)
			IR1_val = ADC_read();  
		else if (flag==1)
			IR2_val = ADC_read();
			
		flag = !flag;
	}
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"
                                                
Serial      pc(USBTX, USBRX, 9600);                                                
AnalogIn    CDS(A0);
DigitalOut  led(LED1);

int main() {
    float measure;
        
    while(1) {
        measure = CDS.read(); // mapping(0~3.3V -> 0.0~1.0)
        measure = measure * 3300; // [mV] (0.0~1.0 -> 0~3300[mV])
        pc.printf("measure = %f mV\n\r", measure);
        
        if (measure < 200) led = 1;
        else               led = 0;
        
        wait(0.2); 
    }
}
```

{% endtab %}
{% endtabs %}

## JADC

{% tabs %}
{% tab title="EC\_2024" %}

```cpp
#include "ecSTM32F4v2.h"
#include "math.h"
//#include "ecADC2.h"


//IR parameter//
uint32_t IR1_val, IR2_val;
PinName_t seqCHn[2] = {PB_0, PB_1};

void setup(void);

int main(void) { 
	// Initialiization --------------------------------------------------------
	setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		printf("IR1 = %d \r\n",IR1_val);
		printf("IR2 = %d \r\n",IR2_val);
		printf("\r\n");
		
		delay_ms(1000);
	}
}

// Initialiization 
void setup(void)
{	
	RCC_PLL_init();                         // System Clock = 84MHz
	UART2_init();							// UART2 Init
	SysTick_init();							// SysTick Init
	
	// JADC Init
	JADC_init(PB_0);
	JADC_init(PB_1);

	// JADC channel sequence setting
	JADC_sequence(seqCHn, 2);
}


void ADC_IRQHandler(void){
	if(is_ADC_OVR())
		clear_ADC_OVR();
	
	if(is_ADC_JEOC()){		// after finishing sequence
		IR1_val = JADC_read(1);
		IR2_val = JADC_read(2);

		clear_ADC_JEOC();
	}
}
```

{% endtab %}

{% tab title="EC" %}

```cpp
#include "stm32f411xe.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecTIM.h"
#include "ecSysTick.h"
#include "ecUART.h"
#include "ecADC.h"
#include "ecPinNames.h"

//IR parameter//
uint32_t IR1_val, IR2_val;
PinName_t seqCHn[2] = {PB_0, PB_1};

void setup(void);

int main(void) { 
	// Initialiization --------------------------------------------------------
	setup();
	
	// Inifinite Loop ----------------------------------------------------------
	while(1){
		printf("IR1 = %d \r\n",IR1_val);
		printf("IR2 = %d \r\n",IR2_val);
		printf("\r\n");
		
		delay_ms(1000);
	}
}

// Initialiization 
void setup(void)
{	
	RCC_PLL_init();                         // System Clock = 84MHz
	UART2_init();							// UART2 Init
	SysTick_init();							// SysTick Init
	
	// JADC Init
	JADC_init(PB_0);
	JADC_init(PB_1);

	// JADC channel sequence setting
	JADC_sequence(seqCHn, 2);
}


void ADC_IRQHandler(void){
	if(is_ADC_OVR())
		clear_ADC_OVR();
	
	if(is_ADC_JEOC()){		// after finishing sequence
		IR1_val = JADC_read(1);
		IR2_val = JADC_read(2);

		clear_ADC_JEOC();
	}
}
```

{% endtab %}
{% endtabs %}

## UART

{% tabs %}
{% tab title="EC\_2024\_1" %}

```cpp
#include "ecSTM32F4v2.h"
#include "math.h"
//#include "ecUART2.h"


static volatile uint8_t PC_Data = 0;
static volatile uint8_t BT_Data = 0;
uint8_t PC_string[]="Loop:\r\n";

void setup(void){
	RCC_PLL_init();
	SysTick_init();
	
	// USART2: USB serial init
	UART2_init();
	UART2_baud(BAUD_9600);

	// USART1: BT serial init 
	UART1_init();
	UART1_baud(BAUD_9600);
}

int main(void){	
	setup();
	printf("MCU Initialized\r\n");	
	while(1){
		// USART Receive: Use Interrupt only
		// USART Transmit:  Interrupt or Polling
		USART2_write(PC_string, 7);
		delay_ms(2000);        
	}
}

void USART2_IRQHandler(){          		// USART2 RX Interrupt : Recommended
	if(is_USART2_RXNE()){
		PC_Data = USART2_read();		// RX from UART2 (PC)
		USART2_write(&PC_Data,1);		// TX to USART2	 (PC)	 Echo of keyboard typing		
	}
}


void USART1_IRQHandler(){          		// USART2 RX Interrupt : Recommended
	if(is_USART1_RXNE()){
		BT_Data = USART1_read();		// RX from UART1 (BT)		
		printf("RX: %c \r\n",BT_Data); // TX to USART2(PC)
	}
}
```

{% endtab %}

{% tab title="EC\_2024\_2" %}

```cpp
#include "stm32f4xx.h"
#include "ecGPIO2.h"
#include "ecRCC2.h"
#include "ecUART2.h"
#include "ecSysTick2.h"

#define MAX_BUF 	10
#define END_CHAR 	13

static volatile uint8_t buffer[MAX_BUF]={0, };
static volatile uint8_t PC_string[MAX_BUF]={0, };
static volatile uint8_t PC_data = 0;

static volatile int idx = 0;
static volatile int bReceive =0;

void setup(void){
	RCC_PLL_init();
	SysTick_init();
	
	// USART2: USB serial init
	UART2_init();
	UART2_baud(BAUD_9600);

	// USART1: BT serial init 
	UART1_init();
	UART1_baud(BAUD_9600);
}

int main(void){	
	setup();
	printf("MCU Initialized\r\n");	
	
	while(1){
		if (bReceive == 1){
			printf("PC_string: %s\r\n", PC_string);				
			bReceive = 0;
		}
	}
}

void USART2_IRQHandler(){          		// USART2 RX Interrupt : Recommended
	if(is_USART2_RXNE()){
		PC_data = USART2_read();		// RX from UART2 (PC)
		USART2_write(&PC_data,1);		// TX to USART2	 (PC)	 Echo of keyboard typing
		
		// Creates a String from serial character receive				
		if(PC_data != END_CHAR && (idx < MAX_BUF)){	
			buffer[idx] = PC_data;
			idx++;
		}
		else if (PC_data== END_CHAR) {						
			bReceive = 1;
			// reset PC_string;
			memset(PC_string, 0, sizeof(char) * MAX_BUF);
			// copy to PC_string;
			memcpy(PC_string, buffer, sizeof(char) * idx);
			// reset buffer
			memset(buffer, 0, sizeof(char) * MAX_BUF);	
			idx = 0;
		}
		else{				//  if(idx >= MAX_BUF)			
			idx = 0;							
			// reset PC_string;
			memset(PC_string, 0, sizeof(char) * MAX_BUF);
			// reset buffer
			memset(buffer, 0, sizeof(char) * MAX_BUF);	// reset buffer
			printf("ERROR : Too long string\r\n");
		}
	}
}
```

{% endtab %}

{% tab title="EC\_2023\_1" %}

```cpp
#include "stm32f4xx.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecUART.h"
#include "ecSysTick.h"


static volatile uint8_t PC_Data = 0;
static volatile uint8_t BT_Data = 0;
uint8_t PC_string[]="Loop:\r\n";

void setup(void){
	RCC_PLL_init();
	SysTick_init();
	
	// USART2: USB serial init
	UART2_init();
	UART2_baud(BAUD_9600);

	// USART1: BT serial init 
	UART1_init();
	UART1_baud(BAUD_9600);
}

int main(void){	
	setup();
	printf("MCU Initialized\r\n");	
	while(1){
		// USART Receive: Use Interrupt only
		// USART Transmit:  Interrupt or Polling
		USART2_write(PC_string, 7);
		delay_ms(2000);        
	}
}

void USART2_IRQHandler(){          		// USART2 RX Interrupt : Recommended
	if(is_USART2_RXNE()){
		PC_Data = USART2_read();		// RX from UART2 (PC)
		USART2_write(&PC_Data,1);		// TX to USART2	 (PC)	 Echo of keyboard typing		
	}
}


void USART1_IRQHandler(){          		// USART2 RX Interrupt : Recommended
	if(is_USART1_RXNE()){
		BT_Data = USART1_read();		// RX from UART1 (BT)		
		printf("RX: %c \r\n",BT_Data); // TX to USART2(PC)
	}
}
```

{% endtab %}

{% tab title="EC\_2023\_2" %}

```cpp
#include "stm32f4xx.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecUART.h"
#include "ecSysTick.h"

#define MAX_BUF 	10
#define END_CHAR 	13

static volatile uint8_t buffer[MAX_BUF]={0, };
static volatile uint8_t PC_string[MAX_BUF]={0, };
static volatile uint8_t PC_data = 0;

static volatile int idx = 0;
static volatile int bReceive =0;

void setup(void){
	RCC_PLL_init();
	SysTick_init();
	
	// USART2: USB serial init
	UART2_init();
	UART2_baud(BAUD_9600);

	// USART1: BT serial init 
	UART1_init();
	UART1_baud(BAUD_9600);
}

int main(void){	
	setup();
	printf("MCU Initialized\r\n");	
	
	while(1){
		if (bReceive == 1){
			printf("PC_string: %s\r\n", PC_string);				
			bReceive = 0;
		}
	}
}

void USART2_IRQHandler(){          		// USART2 RX Interrupt : Recommended
	if(is_USART2_RXNE()){
		PC_data = USART2_read();		// RX from UART2 (PC)
		USART2_write(&PC_data,1);		// TX to USART2	 (PC)	 Echo of keyboard typing
		
		// Creates a String from serial character receive				
		if(PC_data != END_CHAR && (idx < MAX_BUF)){	
			buffer[idx] = PC_data;
			idx++;
		}
		else if (PC_data== END_CHAR) {						
			bReceive = 1;
			// reset PC_string;
			memset(PC_string, 0, sizeof(char) * MAX_BUF);
			// copy to PC_string;
			memcpy(PC_string, buffer, sizeof(char) * idx);
			// reset buffer
			memset(buffer, 0, sizeof(char) * MAX_BUF);	
			idx = 0;
		}
		else{				//  if(idx >= MAX_BUF)			
			idx = 0;							
			// reset PC_string;
			memset(PC_string, 0, sizeof(char) * MAX_BUF);
			// reset buffer
			memset(buffer, 0, sizeof(char) * MAX_BUF);	// reset buffer
			printf("ERROR : Too long string\r\n");
		}
	}
}
```

{% endtab %}

{% tab title="EC\_2022" %}

```cpp
/**
******************************************************************************
* @author  SSSLAB
* @Mod		 2023-10-24 by YKKIM  	
* @brief   Embedded Controller:  Sample Code _ UART2
* 
******************************************************************************
*/
#include "stm32f4xx.h"
#include "ecGPIO.h"
#include "ecRCC.h"
#include "ecUART_simple_student.h"
#include "ecSysTick.h"

int cnt = 0;

void setup(void);

int main(void) {
	// Initialiization --------------------------------------------------------
	setup();
	printf("Hello Nucleo\r\n");
	
	while(1){
		
		printf("Time: %d s\r\n", cnt);
		delay_ms(1000);
		cnt++;
	}

}

// Initialiization 
void setup(void)
{
	RCC_PLL_init();
	SysTick_init();
	UART2_init();
}
```

{% endtab %}

{% tab title="mbed" %}

```cpp
#include "mbed.h"
 
Serial  uart(USBTX, USBRX, 9600);
 
int main(){
    char RXD;    
    while(1)
    {        
        if(uart.readable()){
            RXD = uart.getc();
            uart.printf("%c", RXD);
        }
    }
}
```

{% endtab %}
{% endtabs %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ykkim.gitbook.io/EC/ec-course/example-code.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.